| crypto | Package crypto collects common cryptographic constants. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm | Package kubeadm is the package that contains the libraries that drive the kubeadm binary. |
| k8s.io/kubernetes/cmd/kubeadm/app/util/pkiutil | |
| os | Package os provides a platform-independent interface to operating system functionality. |
| path/filepath | Package filepath implements utility routines for manipulating filename paths in a way compatible with the target operating system-defined file paths. |
| regexp | Package regexp implements regular expression search. |
| runtime | Package runtime contains operations that interact with Go's runtime system, such as functions to control goroutines. |
| runtime/debug | Package debug contains facilities for programs to debug themselves while they are running. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |
| testing | Package testing provides support for automated testing of Go packages. |